System and method for image identification employed thereby

Abstract

A method for image identification is to be implemented using a target and an image sensor. The target is provided with base marks that are non-collinear and that are assigned with distinct identification codes, and an orienting mark that is disposed relative to an imaginary line interconnecting two of the base marks. The image sensor is operable to capture an image of the target that contains the base and orienting marks. The method includes the steps of: evaluating the captured image to determine spatial coordinates of the base and orienting marks; and mapping the determined spatial coordinates into vectors in order to find the orienting mark, and assigning the distinct identification codes to the base marks according to spatial relation of the base marks to the orienting mark. A system that performs the method is also disclosed.

1 . A method for image identification to be implemented using a target and an image sensor, the target being provided with at least three base marks that are non-collinear and that are assigned with distinct identification codes, and an orienting mark that is disposed relative to an imaginary line interconnecting two of the base marks, the image sensor being operable to capture an image of the target that contains the base and orienting marks, the method comprising the steps of: 
 A) evaluating the image captured by the image sensor to determine spatial coordinates of the base and orienting marks; and    B) mapping the spatial coordinates determined in step A) into vectors in order to find the orienting mark, and assigning the distinct identification codes to the base marks according to spatial relation of the base marks to the orienting mark.    
   
   
       2 . The method as claimed in  claim 1 , wherein step B) includes the sub-steps of: 
 B1) forming a first group that includes two of the base marks and the orienting mark, and a second group that includes remaining ones of the base marks;    B2) identifying the orienting mark in the first group; and    B3) assigning the identification codes to the base marks in the first and second groups according to spatial relation of the base marks to the orienting mark identified in sub-step B2).    
   
   
       3 . The method as claimed in  claim 2 , wherein sub-step B1) includes: 
 a) finding a pair of the vectors which form a smallest angle therebetween; and    b) forming the first group that constitutes a vertex and a pair of vector endpoints of the vectors found in sub-step a).    
   
   
       4 . The method as claimed in  claim 2 , wherein sub-step B2) includes: 
 a) finding a pair of the vectors in the first group which form a largest angle therebetween;    b) determining the orienting mark to be at a vertex of the vectors determined in sub-step a).    
   
   
       5 . The method as claimed in  claim 2 , wherein sub-step B3) includes: 
 a) finding a pair of the vectors, a vertex of which is found in the second group, and vector endpoints of which are the two base marks in the first group; and    b) assigning the identification codes to the base marks in the first group according to a vector product of the pair of the vectors found in sub-step a).    
   
   
       6 . The method as claimed in  claim 2 , wherein, in sub-step B1), the number of the remaining ones of the base marks in the second group is greater than two, and wherein sub-step B3) includes: 
 I) forming the second group into a first subset that includes two of the base marks in the second group, and a second subset that includes the remaining ones of the base marks in the second group; and    II) assigning the identification codes to the base marks in the first and second subsets.    
   
   
       7 . The method as claimed in  claim 6 , wherein sub-step I) includes: 
 i) finding a pair of the vectors, a vertex of which is found in the first group, and vector endpoints of which are two of the base marks in the second group, the vectors to be found forming a largest angle therebetween; and    ii) forming the first subset that constitutes the vector endpoints of the vectors found in sub-step i).    
   
   
       8 . The method as claimed in  claim 6 , wherein sub-step II) includes: 
 i) finding a pair of the vectors, a vertex of which is found in the first group, and vector endpoints of which are the two base marks in the first subset; and    ii) assigning the identification codes to the base marks in the first subset according to a vector product of the pair of the vectors found in sub-step i).    
   
   
       9 . A system for image identification, comprising: 
 a target provided with at least three base marks that are non-collinear and that are assigned with distinct identification codes, and an orienting mark that is disposed relative to an imaginary line interconnecting two of the base marks; and    an orientation device including 
 an image sensor operable so as to capture an image of the target that contains the base and orienting marks, and  
 a processor coupled to the image sensor, and operable so as to evaluate the image captured by the image sensor to determine spatial coordinates of the base and orienting marks, so as to map the spatial coordinates determined thereby into vectors in order to find the orienting mark, and so as to assign the distinct identification codes to the base marks according to spatial relation of the base marks to the orienting mark.  
   
   
   
       10 . The system as claimed in  claim 9 , wherein the orienting mark is disposed proximate to the imaginary line.  
   
   
       11 . The system as claimed in  claim 9 , wherein the orienting mark is disposed along the imaginary line.  
   
   
       12 . The system as claimed in  claim 9 , wherein the image sensor is a complementary metal oxide semiconductor light sensor.  
   
   
       13 . The system as claimed in  claim 9 , wherein each of the base and orienting marks is a light source.  
   
   
       14 . The system as claimed in  claim 9 , wherein each of the base and orienting marks is a light-emitting diode.  
   
   
       15 . An orientation device for a system that identifies an image and that includes a target, the target being provided with at least three base marks that are non-collinear and that are assigned with distinct identification codes, and an orienting mark that is disposed relative to an imaginary line interconnecting two of the base marks, the orientation device comprising: 
 an image sensor adapted to capture an image of the target that contains the base and orienting marks; and    a processor coupled to the image sensor, and operable so as to evaluate the image captured by the image sensor to determine spatial coordinates of the base and orienting marks, so as to map the spatial coordinates determined thereby into vectors in order to find the orienting mark, and so as to assign the distinct identification codes to the base marks according to spatial relation of the base marks to the orienting mark.    
   
   
       16 . A target for an image identification system, the target comprising: 
 at least three non-collinear base marks provided on the target and assigned with distinct identification codes; and    an orienting mark disposed relative to an imaginary line interconnecting two of the base marks.    
   
   
       17 . The target as claimed in  claim 16 , wherein the orienting mark is disposed proximate to the imaginary line.  
   
   
       18 . The target as claimed in  claim 16 , wherein the orienting mark is disposed along the imaginary line.  
   
   
       19 . The target as claimed in  claim 16 , wherein each of the base and orienting marks is a light source.  
   
   
       20 . The target as claimed in  claim 16 , wherein each of the base and orienting marks is a light-emitting diode.